不同等级道路对玛纳斯河流域土地利用与景观格局的影响

为揭示不同等级道路对干旱半干旱地区土地利用与景观格局变化的作用过程与机制,以玛纳斯河流域为例,选取1976年玛纳斯河流域不同等级道路为研究对象,基于1976年和2015年两期土地利用分类数据,利用缓冲区分析方法结合土地利用动态度、土地利用程度综合指数以及景观指数,分析近40年间各等级道路缓冲区及缓冲区梯度上土地利用与景观格局的变化规律。结果表明：（1）近40年来玛纳斯河流域各等级道路对流域土地利用变化影响显著且存在梯度效应,即距离道路越远,受各等级道路的扰动就越小;（2）各等级道路对周边整体土地利用变化的影响程度依次为：高速公路与国道>省道与专用道路>县道与乡道;（3）高速公路与国道、省道与专用道路、县道与乡道分别对其缓冲区范围内林地、水域和建设用地的土地利用变化影响最大;（4）近40年来各等级道路不同缓冲区范围内景观破碎度和异质性均有所增加,而景观蔓延度却有所降低;（5）高速公路与国道、省道与专用道路、县道与乡道分别对其两侧3600 m、600 m和300 m范围内景观的切割作用最为强烈,且距离道路越远景观形状受道路的干扰越小,景观形状越趋于规整。

Effects of different level roads on land use and landscape pattern of Manas River Basin

In order to reveal the processes and mechanisms of roads on land use and landscape pattern changes in arid and semi-arid regions, this paper selects the Manas River Basin as the study area, and selects different level roads in this basin in 1976 as the research object. Based on land use classification data covering 1976 and 2015, the method of buffer analysis, combined with land use dynamics, land use comprehensive indexes and landscape indexes, was used to examine the changes of land use and landscape pattern on the road buffer and buffer gradient of all levels in the past 40 years. The results show that the roads of the Manas River Basin have a significant impact on the land use change in recent 40 years and there is a gradient effect: the farther away from the road, the smaller the disturbance of the roads of all levels; the degree of impact of various grades of roads on the overall land use change show that: highway and national roads > provincial roads and special roads > county roads and township roads. In addition, highways and national roads, provincial roads and special roads, county roads and township roads have the greatest impact on the change of forest land, water area and construction land in the buffer zone. The landscape pattern analysis shows that the landscape fragmentation and heterogeneity have increased in different buffer zones of all levels in the past 40 years, but the landscape spread has decreased; the most intense range of the highways and national roads, provincial roads and special roads, county roads and township roads is 3600 meters, 600 meters and 300 meters, respectively, and the farther away from the road, the more the landscape shape is interfered by the road, and the shape of the landscape is more and more regular. This study could provide a reference for the planning of road networks in arid and semi-arid areas and the reasonable development and allocation of land resources.